49ers’ Hunter, Williams hurt on run play

The most costly play of Sunday’s game for the 49ers wasn’t Ted Ginn Jr.’s muffed punt that led to a Saints’ 11-yard touchdown drive, but a 2-yard run by Kendall Hunter on the penultimate play of the third quarter.

No, Hunter didn’t fumble, but he sustained an ankle injury and wide receiver Kyle Williams had a potentially serious knee injury on the play. The 49ers fear Williams might have torn knee ligaments and could be out for an extended period of time, according to ESPN.

Williams was immediately ruled out of the game (Hunter initially was termed questionable to return) and he remained down on the field for several minutes while trainers examined his knee. On the sideline, several of Williams’ teammates and special-teams coach Brad Seely offered words of encouragement.

As is his custom, head coach Jim Harbaugh did not provide injury updates after what he called a “real, rough, tough, physical football game.”

Indeed, San Francisco’s injuries weren’t limited to Hunter and Williams.

In the fourth quarter, tight end Delanie Walker left the game with a hip injury. Walker walked out of the locker room, but was then placed on a cart to get to the team bus, the San Jose Mercury News reported.

Finally, Ginn hurt his hand and wrist, according to Harbaugh, who cited the injury as the reason why Williams replaced Ginn on punt returns after his muffed punt in the second quarter.

If Williams is sidelined for an extended period, it could provide an opportunity for first-round pick A.J. Jenkins to play. Jenkins, who hasn’t played a snap this season, was active only for the season opener. When Mario Manningham was sidelined by a shoulder injury this season, however, Jenkins wasn’t activated and the 49ers dressed four wide receivers.